The present invention relates to a display device not having a backlight unit.
As information-oriented society develops, various flat display devices such as liquid crystal display (LCD) device, plasma display panel (PDPs), electro luminescence display, and vacuum fluorescent display (VFDs) are under study and development.
Among these flat display devices, a display device displays an image using liquid crystals (LCs). Since the display device has a slim profile, low power consumption, a low driving voltage, and is lightweight, it is widely used.
The LCD device has a structure where LCs are interposed between two substrates. The LCD device displays an image using LCs controlled by a voltage applied between the two substrates. Since the LCD device does not emit light spontaneously, it needs a backlight unit for illuminating light from an outside. However, the backlight unit has a limitation of consuming high power.
Furthermore, recently, as demands for large-sized LCD devices increases, a substrate size and a backlight unit are also large-sized.
To meet requirement of a large-sized backlight unit, the length of a lamp increases, so that a lighting time is delayed and power consumption increases due to the increase of the length of the lamp.
Therefore, burden associated with an increase in research and development costs for a large-sized backlight unit increases. Even when huge research and development costs are invested, it is difficult to overcome technical limitations in manufacturing a backlight unit.